COG LCD Display with ST7035 Driver Chip and I2C Interface for Wide Temperature Range (-30~+70℃) Applications

How COG Segment LCDs Work?

1. Glass Substrate:

   • The display is built on a glass panel containing liquid crystal cells.

2. Integrated Driver:

   • The driver IC is mounted directly on the glass, which controls the individual segments of the LCD. This eliminates the need for a flexible PCB (printed circuit board) or external wiring between the glass and the driver, reducing complexity.

3. Polarization:

   • The liquid crystals are aligned between two polarizing layers. When voltage is applied to the segments, the crystals align in a way that blocks or allows light to pass, creating the visible segments.

4. Segment Configuration:

   • The display typically includes a matrix of segments that can be activated or deactivated to form numbers, letters, or custom symbols.

Detailed Parameters:

The following is the introduction of it:

Driver chip: It uses the ST7035 driver chip, which is specifically designed for liquid crystal display, especially for pen segment LCD. It can display static or dynamic information such as numbers and characters.
Interface type: It has an I2C compatible interface, requiring only two signal lines (clock line and data line), which can be easily connected to the microprocessor to achieve data transmission.
Display characteristics: It has a 96-segment and 4 common terminal driving circuit, and is equipped with a 96x4-bit display data RAM (DDRAM), which can store display data. The LCD driving voltage range is 4V to 15V (programmable), with a maximum display frame frequency of 295Hz, and can quickly refresh the display content.
Power supply characteristics: The typical working voltage range of the digital power supply (VDD1, VDD3) and the analog power supply (VDD2) is 3.0V to 5.0V. It has a built-in low-power analog circuit, which helps to save energy.
Package form: It uses COG (Chip On Glass) packaging, binding the chip directly to the glass, featuring a small size and high reliability. Combined with PIN pins, it is convenient for connection with external circuits.
Operating temperature range: The operating temperature is between -40°C and 80°C, capable of adapting to a wide range of environmental temperature changes.

This liquid crystal display is widely used in the following aspects:

Smart wearable devices: Such as smart watches, which can display time, steps, heart rate, etc., and its low power consumption feature is suitable for battery-powered watch devices.
Electronic tags: Used for product labels, logistics labels, etc., which can display product information, logistics status, etc., facilitating information recognition and management.
Portable medical equipment: Such as blood glucose meters, blood pressure monitors, etc., which can clearly display measurement data, making it convenient for users to read.
Industrial instruments: Can be used to display various parameters of industrial equipment, such as temperature, pressure, flow rate, etc., with wide temperature working characteristics suitable for industrial environments.
Handheld instruments: Such as portable multimeters, oscilloscopes, etc., which can display measurement results and related parameters in real time.
Small game consoles: Can be used to display game pictures, scores, etc., providing intuitive visual feedback for players.